1. Field
The subject matter disclosed herein relates to computing devices and systems and more particularly relates to command line interfaces.
2. Description of the Related Art
A command line interface (CLI) provides a method of interacting with a device or software by allowing a user to enter commands into a text terminal, a terminal emulator, or remote shell client. The commands are processed by a command line interpreter which initiates operations that correspond to the entered command. A relatively simple CLI usually displays a prompt to accept a command that is typed by a user and terminated by an enter key. A typical command includes a command name, which designates the type of operation to be performed and a parameter, which may be data, a file, a device or an object on which the operation should be performed. One or more switches flags, or other entries may also be included to modify or control how the operation is executed.
A command should be entered according to the rules of the CLI that processes a command. A CLI can generally be considered as consisting of syntax and semantics. The syntax is the grammar that all commands must follow while the semantics control what operations can be performed and the type of data on which operations can be performed. A CLI is typically used when a large vocabulary of commands or queries, coupled with a wide range of options, can be entered more rapidly as text than with a pure graphical user interface (GUI). CLIs are often used by programmers, system administrators, and technically advanced personal computer users.
Unlike a button or menu item in a GUI, a command line is typically self-documenting, recording exactly what was entered and the results of an entry. For example if a command is entered the CLI may display the output of the command below the command. As more and more text from commands and outputs of commands are generated, the CLI may scroll the text upwards to keep a current command prompt or output in view. Many CLIs will keep the previously entered text of commands and outputs of command visible as long as a session remains open. This can serve as a reference for a user as to what has occurred previously.